Automated mail processing cleaning system

ABSTRACT

A method and apparatus for cleaning dust and particulate from automated mail processing equipment having a conveyer disposed along a plurality of processing stations is provided. The cleaning system includes at least one air nozzle disposed at each station and at least one vacuum port disposed at each station and spaced apart from the air nozzle. A vacuum for creating a vacuum at the vacuum port and an air source for directing air through the air nozzle is provided. A sequencer for allowing air to sequentially pass through the air nozzle at each station while a vacuum is created at the same station is provided. A controller in communication with the sequencer is provided for relaying sequencing information to the sequencer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a Continuation of U.S. patent application Ser. No. 08/277,930,filed Jul. 20, 1994, U.S. Pat. No. 5,465,828, the disclosure of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and apparatus for cleaningmail processing equipment, and in particular to a cleaning system forremoving accumulated dust and particulate from the mail processingequipment.

Modern mail processing equipment is designed to rapidly receive and sortlarge quantities of mail. To accomplish this task, various types of mailprocessing equipment have been employed. Of particular interest to thepresent invention are optical character readers (OCR) such as OCR ModelMLOCR-B, available from Electro Com Automation LP, Arlington, Tex. TheOCR includes a conveyor system which rapidly transports the mail past anoptical character reader which in turn reads information written on theenvelope. This information is then processed by a computer and used tosort the mail.

Also of interest are wide area bar code readers (BCS) such as Model BCS880, available from Electro Com Automation LP, Arlington, Tex. BCSs areused to read the bar code printed by an OCR on an envelope and to sortto a deeper level, i.e. station and carrier route.

Another type of mail processing machine is an advanced canceler system(AFCS), such as Model AFCS FAM 885, available from Electro ComAutomation LP, Arlington, Tex. AFCSs are used to cancel mail arriving atthe post office. They sort the mail into the following categories: (1)OCR readable, (2) non-readable, (3) bar code printed on envelope, (4)business reply, and (5) non-cancelable mail.

Still another type of mail processing machine of interest is a deliverybar code sorter (DBCS), such as Model DBCS II 994, available fromElectro Com Automation LP, Arlington, Tex. DBCSs are similar to the BCSbut have even deeper level of sorting (to carrier walking sequence) andhave more sort bins.

Common to such mail processing equipment are conveyor systems used fortransporting the mail along at least a portion of the equipment. Usuallythe conveyor system will include a pair of spaced-apart belts disposedalong a series of pulleys so that mail can individually be transportedbetween the belts. As mail travels along the conveyor system,particulate is generated within the equipment which can prevent theequipment from remaining in good working order. This problem iscompounded since a large volume of mail is transported by the conveyorsystem causing rapid accumulation of the particulate.

Present methods for removing the accumulated dust and particulaterequire the machines to be shut down for a considerable length of timeso that the accumulated particulate can be accessed for removal. Theparticulate is removed by a blow out procedure which is usually requiredevery two hours on a run of sixteen to eighteen hours per day. The blowout is required for each BCS, OCR, AFCS, and DBCS. However, this blowout is rarely performed because of the extensive down time. Such anextensive down time is undesirable for a variety of reasons includinglabor costs incurred in breaking down and cleaning the equipment andslowing distribution of mail.

It would therefore be desirable to provide a cleaning system for mailprocessing equipment that could reduce or eliminate the down timerequired to remove accumulated particulate from the equipment. Thesystem should also be efficient and economical, and be compatible withexisting mail processing equipment.

2. Description of the Background Art

U.S. Pat. No. 4,221,329 describes the use of an airstream to create a"fluid curtain" in order to prevent accumulation of particulate on aphoto detector.

U.S. Pat. No. 5,245,601 describes the use of ribs on a turntable togenerate air flow to blow dust away from optical equipment.

U.S. Pat. No. 4,441,018 describes an apparatus using temperaturedifferences in air to create air flow to remove particulate fromphotoelectric components of the apparatus.

U.S. Pat. Nos. 5,097,563, 4,603,898, and 4,678,224 describes systems forblowing air over windshields to prevent particulate accumulation on thewindshields.

U.S. Pat. No. 3,469,088 describes the use of a pressurized cleaningfluid for cleaning the lens of a vehicle running light withoutinterrupting the operation of the vehicle.

U.S. Pat. No. 4,187,868 describes the method for cleaning the surface ofan optical element by applying a liquid to the surface and causing theliquid to vibrate.

SUMMARY OF THE INVENTION

A cleaning system for mail processing equipment having a conveyor fortransporting mail is provided. The cleaning system includes an airsupply means for directing a supply of air near the conveyor. Vacuummeans spaced-apart from the air supply means are provided for creating avacuum near the air supply means. A controller is provided for actuatingthe vacuum means during the operation of the air supply means.

In one particular aspect of the cleaning system, the air supply meansincludes a plurality of spaced-apart air nozzles near the conveyor fordirecting a plurality of air streams, and the vacuum means includes avacuum and a plurality of spaced-apart vacuum ports near the conveyor.In a further aspect, the mail processing equipment includes a pluralityof processing stations. At least one air nozzle and at least one vacuumport are disposed at each station with the nozzles being spaced-apartfrom the vacuum ports.

In another particular aspect, a sequencer in communication with thecontroller is provided for sequentially actuating the air nozzles andthe vacuum ports of each air station. In an exemplary aspect, aplurality of air lines are disposed between the sequencer and thenozzles of each station with a separate air line being provided for eachstation. A plurality of vacuum lines are also disposed between thevacuum and the vacuum ports of each station with a separate vacuum linebeing provided for each station.

In yet another aspect, the sequencer is a pneumatic sequencer andincludes a plurality of control valves. The control valves allow air tobe sequentially delivered to each of the air lines. An air gate isdisposed in each of the vacuum lines with each of the air gates being incommunication with one of the lines. Preferably, each air gate is incommunication with the air line that is disposed at the same station atwhich the vacuum line having the air gate is also disposed. Thisconfiguration allows the air gate in the vacuum line to be actuated whenair is delivered through the air line. This provides air to one of thestations while at the same time creating a vacuum at the same station.

In still another aspect, the vacuum ports are disposed in a plenum.Preferably, each station will have a separate plenum.

In an exemplary aspect, the cleaning system is used to clean more thanone piece of mail processing equipment. This is accomplished byproviding a plurality of sequencers which are all in communication withthe controller. Each piece of equipment will include a separatesequencer with each sequencer having a plurality of air lines disposedalong their respective pieces of equipment as previously described. Withthis configuration the controller can provide a signal to sequentiallyactuate each sequencer. This allows each piece of equipment tosequentially be cleaned as dictated by the controller.

In a exemplary embodiment, a cleaning system for a mail opticalcharacter reader having a conveyer disposed along a plurality ofprocessing stations is provided. The cleaning system includes at leastone air nozzle at each station and at least one vacuum port disposed ateach station with the vacuum port being spaced apart from the airnozzle. A vacuum is provided for creating a vacuum at the vacuum port,and an air source is provided for directing air through the air nozzle.A sequencer is provided for allowing air to sequentially pass throughthe air nozzle at each station while a vacuum is created in the vacuumthe same station. A controller in communication with the sequencerprovides sequencing information to the sequencer.

In an exemplary method of the invention, dust and particulate arecleaned from mail processing equipment having a conveyer fortransporting mail by blowing a stream of air over an area of theequipment near the conveyor having the particulate. A vacuum is creatednear the air stream to collect particulate near the air stream. Theblowing and vacuuming steps are repeated along the conveyer.

In one aspect of the method, the air stream is blown over the area byproviding a plurality of nozzles connected to an air source. The vacuumis created by providing a plurality of vacuum ports connected to avacuum source. The vacuum ports are disposed near the conveyor andspaced apart from the air lines. In another aspect of the method, themail processing equipment includes a plurality of processing stationsand at least one nozzle and at least one vacuum port are disposed ateach station. The blowing and vacuuming steps are repeated bysequentially actuating the nozzle and the vacuum port at each station.

In yet another aspect of the method, the mail processing equipmentincludes a plurality of processing stations and the stream of air isblown at the same station at which the vacuum is created. In anotheraspect, the blowing and vacuuming steps are repeated by blowing andvacuuming sequentially along the stations. In a further aspect, thestream of air is blown while simultaneously creating the vacuum.

The invention allows the mail processing equipment to be cleaned dailyand without extensive labor costs. Routine cleaning allows the equipmentto function more efficiently. Furthermore, since daily blow out is notrequired, custodial costs can be reduced as dust is not blown tosurrounding areas and equipment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a cleaning system for an OCR according tothe present invention.

FIG. 2 is a perspective view of an OCR having a cleaning systemaccording to the present invention.

FIG. 3 is a perspective view of a plenum, according to the presentinvention.

FIG. 4 illustrates a feeder station of the OCR of FIG. 2.

FIG. 5 is a detailed view of an interior portion of the feeder of FIG. 4showing a preferred placement of air nozzles according to the presentinvention.

FIG. 6 is a detailed view of an interior portion of a leveler station ofthe OCR of FIG. 2 showing a preferred placement of air nozzles accordingto the present invention.

FIG. 7 illustrates a detailed view of a SCAN-1 and a SCAN-2 station ofthe OCR of FIG. 2 and showing a preferred placement of air nozzles.

FIG. 8 illustrates a detailed view of a portion of the DELAY-1 DELAY-2,AND DELAY-3 stations of the OCR of FIG. 2 and showing preferred nozzleconfigurations according to the present invention.

FIG. 9 is a flow chart illustrating an exemplary method for cleaning anOCR according to the present invention.

DETAILED DESCRIPTION OF THE SPECIFIC EMBODIMENT

The invention provides a cleaning system for removing accumulated dustand particulate from mail processing equipment. According to thecleaning system, a vacuum is provided near areas of the equipment wheredust and particulate tend to accumulate. Operation of the vacuum createsa suction force for removing the particulate from the processingequipment. To further assist in removing the dust and particulate, airis blown through the equipment near the vacuum. The blowing airdisplaces some of the dust and particulate toward the vacuum where itcan be collected.

The cleaning system is particularly adaptable to mail processingequipment having a variety of different processing stations throughwhich mail is directed, usually by a conveyer system as previouslydescribed. For a variety of reasons, including limited vacuum size, itis often desirable to clean only one station at a time. Of course, if asufficient vacuum were provided, all of the stations could be cleanedsimultaneously.

When cleaning only one station at a time, a sequencer is provided tosequentially actuate an air flow and a corresponding vacuum for eachstation. By "sequentially" it is intended to mean that only one stationwill be cleaned at a time. When cleaning is completed at one station,the cleaning process will then begin at another station.

The vacuum will preferably be operational at the same time at which airis being directed through the equipment, i.e., the vacuum and the airstream are simultaneously operated. Alternatively, the vacuum and theair stream can be operated separately or at different times, butpreferably the vacuum will always be operated when air is being directedthrough the equipment.

A controller is provided to deliver sequencing information to thesequencer. Through the controller, the order at which the stations canbe cleaned as well as the length of the cleaning cycles can be dictated.This provides an automated and continuous cleaning cycle.

In one exemplary aspect of the invention, the cleaning system can beused to clean a variety of different pieces of mail processing equipmentincluding BCSs, OCRs, AFCS, and DBCSs. The cleaning system can be usedto effectively clean these pieces of equipment alone or in variouscombinations. As one example, the system could be used to cyclicallyclean three OCRs and two BCSs.

Cleaning a plurality of pieces of cleaning equipment is bestaccomplished by providing a separate sequencer for each piece ofequipment and with each sequencer being in communication with thecontroller. With this configuration, only one vacuum source and one airsource is required if the vacuum and air sources are in communicationwith each piece of equipment. The controller can send a signal to thesequencer for the first piece of equipment to be cleaned. Each cleaningstation of this piece of equipment can then be cleaned in sequence. Oncethe cycle for the first machine is completed, the controller will send asignal to the next sequencer and the next piece of mail processingequipment will be cleaned in the same manner.

Shown in FIG. 1 is a schematic view of an optical code reader (OCR) 10having a cleaning system 11. Although described in the context of anOCR, the system described hereinafter could also be used with othertypes of mail processing equipment including a DBCS, an AFCS, a BCS, andthe like, as previously described. For purposes of clarity, however, thecleaning system 11 will be described only in connection with an OCR.

The OCR 10 includes a plurality of processing stations 12. Not shown isa conveyer system disposed along the OCR 10 which transports mailbetween the stations 12. Disposed at each station 12 are a plurality ofair nozzles 14 for directing air through the OCR 10. As described inmore detail hereinafter, the nozzles 14 are preferably disposed nearareas in the OCR 10 where a significant amount of particulate istypically generated.

Spaced apart from the air nozzles 14 are a plurality of vacuum ports 16.The vacuum ports 16 are disposed so that each processing station 12includes at least one port 16. A vacuum 18 is connected to the ports 16by a plurality of vacuum lines 20. Preferably, each station 12 will havea single vacuum line 20. The vacuum lines 20 are connected to the vacuum18 by a common line 22. Disposed in the common line 22 is a main vacuumgate 24. When the main vacuum gate 24 is opened and the vacuum 18activated, a vacuum is supplied to each of the vacuum lines 20. Tocontrol the number of stations 12 receiving the vacuum, each vacuum line20 is provided with a vacuum line gate 26. The vacuum line gates 26 canbe opened and closed as desired depending upon the number of stations 12which are to receive the vacuum.

Air is provided to the air nozzles 14 by a plurality of air lines 28.Preferably, each station 12 will have a separate air line 28. The airlines 28 are connected to a pneumatic sequencer 30 having a plurality ofair gates 32. The air gates 32 can be opened and closed as desireddepending on which stations 12 are desired to receive the air.Compressed air is delivered to the air lines 28 by an air source 34.

In an exemplary embodiment, the vacuum line gates 26 are connected tothe pneumatic sequencer 30 by a plurality of air lines 31 that areseparate from air lines 28. Preferably, each gate 26 has two air lines,with one of the line 31 being used to open the gate 26, and the otherbeing used to close the gate 26. The sequencer 30 includes a pluralityof vacuum gate valves (not shown) to control air delivery through theseair lines so that the vacuum in the processing stations 12 can becreated independently from the delivery of air through nozzles 14.Preferably, the controller 36 will signal the sequencer 30 to direct airthrough at least one of the air lines 28 at the same time air isdirected through at least one of the air lines 31 disposed to open oneof the air gates 26. This allow air to be directed through the stations12 at the same time that the vacuum is created. Preferably, air will bedirected through the air line 28 having the same station 12 in commonwith the opened air gate 26 so that the air and vacuum will be createdsimultaneously at the same station 12.

In an alternative embodiment, air lines 31 are removed and each air line28 is placed in communication with the vacuum line gate 26 having thesame station 12 in common. When air is provided to one of the air lines28, air will be directed through the nozzles 14 of the associatedstation 12 and also into the vacuum line gate 26 of the same station 12.This simultaneously opens the vacuum line gate 26 and creates a vacuumat the vacuum port 16 for the same station 12 receiving the air from thenozzles 14, i.e., a vacuum and an air flow are simultaneously created atthe same station. Hence, once the vacuum 18 is activated and the mainvacuum gate 24 is opened, air directed through any one of the air lines28 will cause air to flow through a particular station 12 and willsimultaneously create a vacuum at the same station.

To determine the order of station cleaning, a controller 36 incommunication with the pneumatic sequencer 30 is provided. Thecontroller 36 sends signals to the pneumatic sequencer 30 to instructthe sequencer 30 as to the order to which the air valves 32 should beopened. When more than one piece of mail processing equipment isincluded in the cleaning system, the controller 36 sends signals to thesequencers 30 of each piece of equipment to dictate the order ofequipment cleaning.

Exemplary controllers 36 include an IDEC FA 2J or FA3S PLC, commerciallyavailable from supplies such as Steven Engineering, South San Francisco,Calif. Such controllers can be provided with a 4 kilobyte electricallyerasable programmable read only memory (EEPROM) so that the controllersprogramming is not lost during power outages or brown-outs. Thecontroller 36 is connected to the pneumatic sequencer 30 by a variety ofinput and output devices. These input and output devices are also usedto connect the controller to the vacuum 18 and to the OCR 10. Thisallows the controller 36 to actuate the vacuum 18 and to receive signalsfrom the OCR 10 regarding its state of operation. After receiving suchsignals from the OCR 10, the controller 36 can determine whether it isproper to proceed with the cleaning cycle. If the signals indicate thatit is proper to proceed, the controller 36 signals the pneumaticsequencer 30 to begin the cleaning cycle.

An exemplary pneumatic sequencer 30 is a Pneumatic Control and airsource, commercially available from RTU Electronics, Sacramento, Calif.The pneumatic sequencer 30 can be provided with two control sides, avacuum gate control side and a compressed air control side. On thecompressed air control side are the air gates 32. Preferably, gates 32are solenoid valves and are connected to polyethylene tubing which formsthe air lines 28. Signals received from the controller 36 are used toopen the air control solenoid valves 32 which deliver compressed airthrough the air lines 28. When the air lines 28 are connected to boththe nozzles 14 and the vacuum line gates 26 both compressed air and avacuum can be created simultaneously at the same station 12.

As previously described, a plurality of vacuum control solenoid valves(not shown) can alternatively be provided on the vacuum gate controlside of the sequencer 30 (not shown). The vacuum control solenoid valvescan be directly connected to the vacuum line gates 26 by tubing so thata vacuum can be provided at each station 12 independently of thecompressed air delivery through the lines 28. To control the opening ofthe vacuum line gates 26, the controller 36 can be configured to send asignal to the pneumatic sequencer 30 to open the vacuum control solenoidvalves which in turn deliver air to the vacuum line gates 26 to providethe vacuum. The controller 36 can be configured so that the air controlsolenoid valve and the vacuum control solenoid valve having the samestation in common are simultaneously opened to simultaneously providecompressed air and a vacuum at the common station.

An exemplary vacuum is a 15 H.P. Industravac, commercially availablefrom Thomas Air Systems, Inc., South San Francisco, Calif. Such a vacuumis able to create sufficient suction at each of the stations 12 toremove the particulate. During a cleaning cycle, the vacuum 18 willpreferably be in continuous operation with the gates 26 being used tochannel or direct the vacuum to the desired station 12.

Although not shown, the controller 36 can be in communication with aplurality of OCRs 10 (or similar types of mail processing equipment),with each OCR 10 being provided with a pneumatic sequencer 30 andcorresponding air and vacuum lines. As previously described, the samevacuum 18 can be used to produce the vacuum for each of the OCRs 10.This is best accomplished by providing a plurality of common lines 22(and associated main vacuum gates 24) which are each connected to thevacuum lines 20 of each OCR 10. The main vacuum gates 24 when placed incommunication with the controller 36 can then be used to control whichOCRs 10 are to receive the vacuum.

Before a cleaning cycle is begun on a particular OCR 10, the controller36 receives various signals from the OCR 10 to determine if the OCR 10is ready for cleaning. In one particular aspect, a "stop line" signal isreceived from the OCR 10 indicating whether the OCR's cover or panel isopen so that compressed air will not be activated while the cover orpanel is open. Another signal is a "process" signal which indicateswhether the OCR 10 is out of service. If the OCR 10 is not operational,then cleaning is not necessary and the controller 36 will not begin thecycle for that OCR 10. Another signal is a "no mail" signal. Asdescribed in more detail hereinafter, this signal allows for compressedair to be delivered to the feed section of the OCR 10 between cycles.

Referring to FIG. 2, a perspective view of an OCR 38 is shown. The OCR38 includes a variety of processing stations including a feeder/levelerstation 40, a SCAN-1 station 42, a SCAN-2 station 44, a DELAY-1 station46, a DELAY-2 station 48, and a DELAY-3 station 50. Mail is introducedto the OCR 38 at the feeder/leveler station 40 where it passes throughthe SCAN and DELAY sections 42-50. Information read from the mail isdelivered to a computer system 52 through a conduit 54 and is used tosort the mail into various sorting stations 56. Attached to the stations40-50 are plenums 58a-58g, respectively, for creating a vacuum at thestations. Attached to each plenum is a vacuum line 60 which is connectedto a vacuum (not shown). Attached to the OCR 38 by a frame 62 is apneumatic sequencer 64. Connected to the pneumatic sequencer 64 are aplurality of air lines 66. Although shown discontinued in FIG. 2, theair lines 66 continue to each station 40-50 where they are used toprovide compressed air to the stations as previously described inconnection with FIG. 1. Connected to the vacuum, the sequencer 64 andthe OCR 38 is a controller (not shown) which is used to actuate andcontrol the cleaning cycle as previously described.

Referring to FIG. 3, a plenum 58 will be described in greater detail.The plenum 58 includes a vacuum line connection 68 and a plurality ofvacuum ports 70. The plenum 58 serves essentially as a manifold todistribute suction at the vacuum line connection 68 to the vacuum ports70.

Referring to FIGS. 4-8, the stations 40-50 will be described in greaterdetail to show an exemplary placement of various air direction deviceswithin the stations 40-50. The particular placement of these deviceswithin the stations 40-50 is only one type of placement scheme that hasbeen found to be particularly effective. However, other placementschemes can also be provided and are considered to be within the scopeof this invention. Shown in FIG. 4 is a feeder section 72 of thefeeder/leveler station 40 of FIG. 2. Mail is initially placed on ahorizontal belt 74 where is it fed into a friction separator assembly76. Attached to the separator assembly 76 is the plenum 58a which isused to create the vacuum in the separator assembly 76. The separatorassembly 76 is shown in greater detail in FIG. 5. The separator assembly76 preferably includes an air nozzle 78 and a air knife 80 fordelivering air to the assembly 76 in the direction indicated by thearrows. Preferably, the air nozzle 78 will be a 90° nozzle 1/4" NPT, andthe air knife 80 will be an ionic air knife having a length of about 6inches. The air nozzle 78 and air knife 80 are connected to thepneumatic sequencer 64 of FIG. 2 by the air lines 66 (shown in FIG. 2).When air is directed through the nozzle 78 and the air knife 80, thecompressed air displaces particulate in the assembly 76 which iscollected by the vacuum ports 70 of the plenum 58a.

Referring to FIG. 6, an interior portion of a leveler section 82 of thefeeder/leveler 40 of FIG. 2 is shown. The leveler section 82 preferablyincludes two air nozzles 84 (one nozzle 84 shown elevated for purposesof clarity). The air nozzles 84 direct air as indicated by the arrows.Preferably, the air nozzles 84 will be whirl jet 90° nozzles 3/8" NPT.The nozzles 84 are connected to the air lines 66 of FIG. 2 as previouslydescribed. When air is directed through the nozzles 84, particulate isdisplaced so that it can be removed through the vacuum ports 70 of theplenum 58b. Alternatively, other types and sizes of nozzles can also beused and can also be placed in other locations on the leveler section82.

Shown in FIG. 7 is the SCAN-1 42 and the SCAN-2 44 stations of the OCR38 of FIG. 2. For purposes of clarity, the conveyor belts have beenremoved and only the pulleys 85 are shown. The SCAN-1 station 42includes a plurality of air nozzles 86. These nozzles will preferably beselected from the group consisting of flat jet nozzles, fan jet nozzles,adjustable fan jet nozzles, and the like. The nozzles 86 are disposed sothat when air is directed through the nozzles, particulate is displacedwhere it can be evacuated from the SCAN-1 station 42 by the vacuum port70 of the plenum 58c. Disposed in the SCAN-2 station 44 are a pluralityof air nozzles 88 and an air knife 90. The air nozzles 88 will bepreferably selected from the group consisting from flat jet nozzles,shower head nozzles and 90° nozzles. Preferably, the air knife 90 willbe a 24" ion air knife and will direct air towards the plenum 58d asindicated by the arrows. As with the other stations, other types ofnozzles and other types of configurations can be used.

Referring now to FIG. 8, an interior portion of DELAY-1 station 46 isshown (with a portion of belts 91 removed for clarity). This interiorportion is essentially identical to the interior portions of the DELAY-2and DELAY-3 stations 48, 50 and preferably includes essentially the samenozzle configurations. Hence, for purposes of clarity, only the interiorportion of DELAY-1 station 46 will be described. Not shown in FIG. 8 isthe plenum 58e which is located opposite three air nozzles 92. The airnozzles 92 are preferably 90° whirl jet nozzles 3/8" NPT and direct airtoward the plenum as indicated by the arrows. As with the otherstations, the number, type, and configuration of the nozzles can bevaried as desired.

The ionic air knives shown in FIGS. 5 and 7 remove the static charge ofthe dust particulate for easier removal from the base plate of theequipment. As the belts in the equipment turn around the pulleys, acharge of static electricity is built up on the base plate holding thepulleys. The ionic air knife releases air through a long slit whichprovides a curtain of air which passes over a line of ion emitters whichare charged by a power supply for the knife. As static builds, the dustand particulate are attracted to the base plate similar to a magnet. Theblast of ionic air reverses this charge and dust is freely removed tothe vacuum plenum. The static electricity, in general, is also reducedin the SCAN and FEED areas where these knives are located which reducesthe potential for data loss in the equipment's computer.

Referring to FIG. 9, an exemplary method for cleaning an OCR isdescribed. According to the method, a main vacuum gate that is connectedto the vacuum source is opened to provide a vacuum to the vacuum stationgates of the first OCR to be cleaned. The feeder/leveler vacuum gate isfirst opened while simultaneously directing compressed air through thefeeder/leveler for a time period, t1. Preferably, the compressed air andvacuum will be activated for a time in the range from about 10 secondsto 20 seconds, more preferably for about 15 seconds. The feeder/levelervacuum gate is then closed and air is deactivated through thefeeder/leveler. The vacuum gate for the SCAN-1 station is then openedwhile simultaneously directing air through SCAN-1 station for the timet1. Alternatively, the air and vacuum can be activated for a timedifferent than t1 as required. The SCAN-1 gate is then closed and theair is deactivated through the SCAN-1 station. This same sequence isthen followed in succession for the SCAN-2, the DELAY-1, the DELAY-2,and the DELAY-3 stations, respectively. Alternatively, the order inwhich the stations are cleaned can be varied as required. Once all ofthe stations have been cleaned, the main vacuum gate for the first OCRis closed, and the main vacuum gate for the second OCR (or another mailprocessing device) is opened. The second OCR is then cleaned using thesame cycle as previously described for the first OCR. Alternatively, thesecond OCR can be cleaned using a different sequence than in the firstOCR depending upon the particular application and the particularaccumulation of particulate in the second machine. After the second OCRis completed, the main vacuum gate for the second OCR is closed, andanother OCR or similar device is cleaned as previously described. Afterall of the OCRs are cleaned, a rest period is started. The rest periodwill occur for about 10 minutes to 15 minutes, more preferably for about12 minutes. During the rest period, the vacuum will preferably remainoperational and will be stationed at the feeder/leveler station of oneof the OCRs until the next cleaning cycle is sequenced. The vacuumstationing during the rest period is preferably alternated to anotherOCR after each cleaning. After the rest period, the cleaning cycle isagain initiated so that each of the OCRs can be cleaned. This processcontinues automatically until stopped by the controller.

The stationing of the vacuum at the feeder/leveler station during therest period is preferable because the feeder/leveler station usuallyreceives the most particulate. Hence, while the cycle is in the restperiod, the vacuum can be used to further clean the feeder/levelerstation. As previously described, the OCR can send a signal to thecontroller to indicate a no mail situation. This signal indicates thatthere is no mail available at the feed section during the rest period.Since no mail is present, the controller can send a signal to activate acleaning cycle for that OCR during the rest period. This providesadditional cleaning between cleaning cycles.

The present invention has been described in detail. However,modifications and variations may occur to those skilled in the artwithout departing from the principles of the claimed invention.Therefore, the scope of the invention should be determined primarilywith reference to the appended claims, along with the full scope ofequivalence to which those claims are entitled by law.

What is claimed is:
 1. A cleaning system for mail processing equipmenthaving a conveyor for transporting mail, the system comprising:airsupply means for directing a supply of air near the conveyor; vacuummeans spaced apart from the air supply means for creating a vacuum nearthe air supply means, wherein said vacuum means comprises a vacuumplenum having a plurality of spaced apart vacuum ports near theconveyor; and a controller for actuating the vacuum means duringoperation of the air supply means.
 2. A cleaning system for mailprocessing equipment having a conveyor for transporting mail, the systemcomprising:a vacuum source; and a vacuum plenum having a vacuum lineconnection and a plurality of vacuum ports, wherein the vacuum source isconnected to the vacuum line connection, and wherein the plenum isconnected to the mail processing equipment with the vacuum portsgenerally facing the conveyor so that a vacuum produced by the vacuumsource will be created at selected points along the conveyor where thevacuum ports are located.
 3. A cleaning system as in claim 2, whereinthe vacuum plenum includes a housing, and wherein the vacuum portscomprise openings in the housing.
 4. A cleaning system as in claim 3,wherein the openings are round in geometry.
 5. A cleaning system as inclaim 2, further comprising at least one air nozzle spaced apart fromthe vacuum plenum.
 6. A mail processing machine for processing mail,said machine comprising:at least one mail processing station; at leastone elongate conveyor on said at least one processing station whichtransports the mail along said processing station; and at least onevacuum plenum having a plurality of vacuum ports, wherein the vacuumplenum is connected to said processing station with the vacuum portsgenerally facing tile conveyor so that a vacuum may be created atselected points along the conveyor where the vacuum ports are located.7. A mail processing machine as in claim 6, wherein the vacuum plenumincludes a housing, and wherein the vacuum ports comprise openings inthe housing.
 8. A mail processing machine as in claim 7, wherein theopenings are round in geometry.
 9. A mail processing machine as in claim6, wherein the vacuum plenum further includes a vacuum sourceconnection.
 10. A mail processing machine as in claim 6, furthercomprising at least one air nozzle at said processing station, said airnozzle being spaced apart from said vacuum plenum.
 11. A method forcleaning a piece of mail processing equipment having at least oneelongate conveyer which transports mail, said methodcomprising:providing at least one vacuum plenum having a plurality ofvacuum ports which are positioned to generally face the conveyer;blowing air across the conveyer at selected points where mailparticulate tends to accumulate; and applying a vacuum to the plenum tocreate a vacuum at selected points along the conveyer where the vacuumports are located, wherein the vacuum at the selected points issufficient to draw accumulated mail particulate from the mail processingequipment and into the plenum.
 12. A method as in claim 11, furthercomprising directing compressed air in the direction of the vacuumplenum to move the accumulate particulate toward the plenum.